Spiraea ×pyramidata

Spiraea ×pyramidata Greene

Pittonia 2: 221. 1892.

Endemic
Synonyms: Spiraea menziesii var. pyramidata (Greene) Piper S. tomentulosa Rydberg
Treatment appears in FNA Volume 9. Treatment on page 408. Mentioned on page 400.

Shrubs, 3–15 dm. Stems erect to spreading, branched. Leaves: petiole 2–5 mm; blade elliptic to obovate, 2–6 (–9) × 0.5–4 cm, chartaceous, base cuneate, margins doubly serrate distally from middle, venation pinnate craspedodromous, secondary-veins prominent, apex acute to obtuse, abaxial surface puberulent to pubescent, adaxial glabrous. Inflorescences mostly terminal, hemispheric to obconic panicles, 5–15 × 3–10 cm height 1–1.5 times diam.; branches pubescent. Pedicels 1–3 mm, pubescent. Flowers 2–4 mm diam.; hypanthia hemispheric, 1 mm, abaxial surface tomentose, adaxial pubescent; sepals ovate, 1.5–2.5 mm; petals white to pink, ovate to obovate, 1.5–2.5 mm; staminodes 10–15; stamens 20–30, 2 times petal length. Follicles oblanceoloid, 1.5–2 mm, shiny, glabrous. 2n = 36.


Phenology: Flowering May–Jul; fruiting Jun–Nov.
Habitat: Disturbed sites, riparian zones, flood plains, scree slopes, dry canyon slopes, moist open forest and woodland edges, clearings, roadsides, railways, campsites, home or farm sites
Elevation: 200–1500 m

Distribution

V9 687-distribution-map.jpg

B.C., Idaho, Mont., Oreg., Wash.

Discussion

Examining morphological characters of the leaf and flower, tests of pollen viability, cytological study of chromosomes, cultivation studies of seeds, cuttings, and live plants, assessment of pollinators, and controlled hybrid experiments led W. J. Hess (1969) to conclude that Spiraea ×pyramidata is a natural hybrid of S. douglasii var. menziesii and S. lucida. Hess found also that populations of S. ×pyramidata in Washington are more distinct and no introgression appeared to occur from the parental taxa; populations in British Columbia were less distinct and had more mixed populations with hybrids, parents, and probable introgressants. Hess determined that S. ×pyramidata is particularly adapted to colonization of open disturbed sites such as roadsides, railways, forest camps, and homesteads that occur in proximity to both parents. Once established, the hybrid spreads extensively by rhizomes.

Selected References

None.

Lower Taxa

None.
... more about "Spiraea ×pyramidata"
tomentose +, puberulent +  and pubescent +
acute;obtuse +
Richard Lis +
Spiraea ×pyramidata Greene +
reddish +  and dark-brown gray or gray-black +
not +  and exfoliating +
compound +  and simple +
opposite +  and alternate +
cuneate +
6 cm60 mm <br />0.06 m <br /> (9 cm90 mm <br />0.09 m <br />) +
2 cm20 mm <br />0.02 m <br /> (6 cm60 mm <br />0.06 m <br />) +
elliptic +  and obovate +
1 cm10 mm <br />0.01 m <br /> (10 cm100 mm <br />0.1 m <br />) +
coriaceous +, chartaceous +  and membranous +
0.5 cm5 mm <br />0.005 m <br /> (?) +  and 4 cm40 mm <br />0.04 m <br /> (?) +
glabrate +  and tomentose +
B.C. +, Idaho +, Mont. +, Oreg. +  and Wash. +
not +  and aggregated +
200–1500 m +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
unisexual +  and bisexual +
oblanceoloid +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
0.05 cm0.5 mm <br />5.0e-4 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
tomentose +  and glabrous +
5;4;5;4;5;4;5;4;5;4 +
list +  and count +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
coriaceous +
not +  and aggregated +
not +  and aggregated +
Disturbed sites, riparian zones, flood plains, scree slopes, dry canyon slopes, moist open forest and woodland edges, clearings, roadsides, railways, campsites, home or farm sites +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
glabrous +  and hairy +
hemispheric +
1 cm10 mm <br />0.01 m <br /> (?) +
(2-)3-1000+-flowered +
1-1.5 times diam +
5 cm50 mm <br />0.05 m <br /> (?) +  and 15 cm150 mm <br />0.15 m <br /> (?) +
axillary +  and terminal +
hemispheric +  and obconic +
3 cm30 mm <br />0.03 m <br /> (?) +  and 10 cm100 mm <br />0.1 m <br /> (?) +
crassinucellate +
compound +  and simple +
deciduous +
craspedodromous +
pinnate +  and serrate +
toothed +, unlobed +  and lobed +
inferior +  and superior +
biseriate +  and clustered +
collateral +  and apical +
racemiform +  and corymbiform +
glabrous +  and hairy +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
0 (?) +  and 4 (?) +
white +  and pink +
free +  and distinct +
ovate;obovate +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
0.2 cm2 mm <br />0.002 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering May–Jul +  and fruiting Jun–Nov. +
adnate +, free +, connate +  and distinct +
not arillate +
fusiform;oblong +
0.2 cm2 mm <br />0.002 m <br /> (?) +  and 0.4 cm4 mm <br />0.004 m <br /> (?) +
deciduous +  and persistent +
free +  and distinct +
reflexed +, erect +, ascending +  and spreading +
0.15 cm1.5 mm <br />0.0015 m <br /> (0.25 cm2.5 mm <br />0.0025 m <br />) +
2 +  and 4 +
free +  and distinct +
2 times petal length +
shorter or longer +
nectariferous +
reddish-brown +  and brown +
decumbent +  and prostrate +
erect +  and spreading +
villous;glabrous +
5 +  and 20 +
discoid +  and capitate +
deciduous +  and persistent +
distinct +
subterminal +  and terminal +
not elongate +
hairy +  and glabrous +
Spiraea menziesii var. pyramidata +  and S. tomentulosa +
Spiraea ×pyramidata +
species +
inconspicuous +
reduced +